Roller cover for a floor-cleaning machine and floor-cleaning machine with a roller cover

ABSTRACT

A roller cover for a floor-cleaning machine with a housing, a cleaning roller, a drive, a dirt container, and a dirt strip. The housing having a rear wall and defining an opening that faces a floor surface during operation of the roller cover. The cleaning roller includes a cleaning element that extends through the opening. The drive rotationally powers the cleaning roller such that the cleaning roller rotates toward the rear wall. The dirt container is disposed in the housing and faces away from the rear wall. The dirt strip has a bottom edge that is arranged on that side of a longitudinal axis of the cleaning roller that faces the rear wall and configured to engage a surface of a floor. The dirt strip is movably coupled to the housing to permit changes in the distance between the bottom edge and the longitudinal axis.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit and priority of German Patent Application No. 10 2022 111 606.9, filed May 10, 2022, the disclosure of which is incorporated by reference as if fully set forth in detail herein.

FIELD

The present disclosure relates to a roller cover for a floor-cleaning machine and a floor cleaning machine having a roller cover.

BACKGROUND

Roller covers of this type are known from the prior art. First of all, a housing is provided which is fitted preferably in a height-adjustable manner to the machine housing of a floor-cleaning machine, wherein a cleaning roller, frequently in the form of a brush roller, is accommodated in a manner driven rotationally in the housing. During the operation, cleaning liquid is applied to the floor surface being cleaned in front of the brush roller, as seen in the direction of movement of the floor-cleaning machine, and therefore the brush roller engages with the floor surface in the region which has previously been wetted with cleaning liquid. The engagement with the brush roller causes dirt to be detached from the floor surface being cleaned. Behind the roller cover, as seen in the direction of movement of the machine, there is then provided a dirty liquid receiving device, generally in the form of what is referred to as a suction foot, with which the cleaning liquid which has remained on the floor surface being cleaned is sucked up again with the aid of a negative pressure source.

Furthermore, it is known that a dirt container is additionally provided in the housing of the roller cover, said dirt container being arranged in such a manner that dirt which is detached by the brush roller is hurled into the dirt container.

One possibility here is to arrange the dirt container in such a manner that it is arranged in front of the brush roller, as seen in the direction of movement which the circumference of the brush roller has along the line in which said circumference is in contact with the floor surface being cleaned. Dirt then has to be hurled away forwards in the direction of the dirt container only at a relatively acute angle to the floor surface. This is referred to as the “forward throwing” principle.

However, this gives rise to the problem that, when the circumference of the brush roller moves in the direction of travel on the line along which the brush roller engages with the floor surface being cleaned, dirt-laden liquid is likewise hurled forwards in the direction of travel. Dirt is therefore conveyed away from the suction volume located behind the roller cover. When the brush roller rotates in such a manner that the circumference thereof moves counter to the direction of travel in the line in which the circumference is in contact with the floor surface being cleaned, the dirt container has to be arranged between the roller cover and the dirty liquid receiving device, which increases the distance between them and is therefore likewise problematic.

Furthermore, it is known from the prior art to provide two counter-rotating brush rollers in the roller cover, wherein the roller cover is constructed in such a manner that dirt-laden liquid thrown up by the brush rollers is conveyed around the upper section of a roller into a dirt container, wherein the dirt container is arranged behind the brush roller with respect to the direction of movement of the circumference of the brush roller along the line along which the brush roller is in contact with the floor surface being cleaned. A design of this type is based on the “overhead throwing” principle. The design which has two counter-rotating brush rollers which each convey the dirty liquid upwards and around a roller has the disadvantage, however, that dirty liquid tends to be squeezed out laterally from the roller cover. This is associated in turn with the requirement of additionally providing squeegees at the sides of the roller cover, the squeegees preventing liquid from flowing laterally out of the region which is covered by the roller cover. However, such lateral squeegees are associated with the disadvantage that they become worn and also increase the width of the roller cover.

In addition, the further problem arises that the brush rollers are intended to have a certain minimum size. This is because small brush rollers because of their short bristle bundles cannot convey very large objects (debris), do not enter unevennesses in the floor to a sufficient depth and also become worn more rapidly. If two brush rollers are therefore intended to be used, this also causes a certain constructional size, which is disadvantageous since the space available for the roller cover on the machine housing is limited and a compact construction is desirable because handling is easier.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

One object of the present disclosure is the provision of a roller cover and a floor-cleaning machine with a roller cover, wherein the roller cover has as large a working width as possible in relation to the width of the roller cover and it is ensured that dirt-laden liquid remaining on a floor surface being cleaned can reliably enter the region of a dirty liquid receiving device arranged behind the roller cover.

This object can be achieved by a roller cover for a floor-cleaning machine, with a housing, wherein the housing has a housing wall arrangement which delimits a housing interior and which comprises a rear wall and two opposite side walls and which has an opening which is arranged so as, during the operation of the roller cover to face a floor surface to be cleaned, with a cleaning roller, which extends along a longitudinal axis and has at least one cleaning element radially on the outside, wherein the cleaning roller extends along its longitudinal axis through the housing interior from the first side wall to the second side wall, wherein the at least one cleaning element of the cleaning roller extends through the opening, with a drive which is coupled to the cleaning roller in order to drive the latter rotationally, wherein the drive is configured in such a manner that, whenever the cleaning roller is driven, that part of the cleaning roller which is provided to engage with a floor surface to be cleaned rotates towards the rear wall, wherein a dirt container is arranged in the housing interior on that side of the cleaning roller which faces away from the rear wall, wherein fitted to the housing wall arrangement is a dirt strip arrangement which has a bottom edge which runs parallel to the longitudinal axis and is configured to rest on a floor surface to be cleaned, wherein the dirt strip arrangement is held on the housing wall arrangement in such a manner that the bottom edge is arranged on that side of the longitudinal axis of the cleaning roller which faces the rear wall, and wherein the dirt strip arrangement is held movably on the housing wall arrangement such that the distance of the bottom edge from the longitudinal axis, as seen perpendicularly to the longitudinal axis and perpendicularly to the plane of the opening, can be changed.

The roller cover can have a housing which in turn has a housing wall arrangement which, inter alia, comprises a rear wall and two side walls preferably extending away therefrom. In addition, an opening is provided in the housing wall arrangement, said opening, when the roller cover is in operation and is moved over a floor surface being cleaned, faces the floor surface being cleaned. In addition, a cleaning roller is provided which extends along a longitudinal axis and has at least one cleaning element which is arranged radially on the outside, preferably around a roller core. The cleaning roller is arranged here in the housing in such a manner that the cleaning element extends with one part through the opening and is therefore capable, during operation of the roller cover, of engaging with the surface being cleaned and over which the roller cover is moved.

Furthermore, a drive is provided on the roller cover, said drive being coupled to the cleaning roller in order to drive the latter rotationally. The drive is configured in such a manner that it drives the cleaning roller with such a direction of rotation that that part of the cleaning roller which extends through the opening and is provided to engage with a floor surface being cleaned moves towards the rear wall. In other words, the circumference of the cleaning roller in the line in which the cleaning roller is in contact during operation with the floor surface being cleaned moves towards the rear wall. The roller cover according to the present disclosure is therefore configured as a “co-rotator”. This is because, by rotation of the brush roller, a certain propulsion is exerted in the forwards direction on the roller cover, i.e., a floor-cleaning machine with the roller cover according to the disclosure is not braked when the roller cover is in operation, but rather an additional propulsion is exerted by the roller cover. In the case of smaller machines, this can even make a drive superfluous.

Furthermore, a dirt container is arranged in the housing interior on that side of the cleaning roller which faces away from the rear wall, and therefore in the front region in front of the cleaning roller, said dirt container being configured so as, during the operation of the roller cover, to receive dirt thrown up by the cleaning roller from a floor surface being cleaned, wherein said dirt is hurled around the cleaning roller according to the “overhead throwing” principle before it enters the dirt container.

Furthermore, a dirt strip arrangement is provided which is fitted to the housing wall arrangement and has a bottom edge which runs parallel to the longitudinal axis and is also configured to rest on a floor surface being cleaned when the roller cover, fitted to a floor-cleaning machine, is moved with the latter over the floor surface being cleaned. In addition, the dirt strip arrangement is held on the housing in such a manner that the bottom edge is arranged on that side of the longitudinal axis of the cleaning roller which faces the rear wall. The dirt strip arrangement is therefore fitted behind the cleaning roller, as seen in the normal direction of movement of the roller cover, and serves to collect dirty liquid and dirt thrown up rearwards by the cleaning roller. Finally, according to the disclosure, the dirt strip arrangement can also be held on the housing wall arrangement in such a manner that the distance of the bottom edge from the longitudinal axis, as measured perpendicularly to the longitudinal axis and likewise perpendicularly to the plane of the opening through which the cleaning roller extends out of the housing, can be automatically changed. As a result, the position of the dirt strip arrangement relative to the housing wall arrangement can be automatically adjusted in a direction perpendicularly to the floor surface being cleaned, and therefore a changing length in the radial direction of the cleaning elements on the cleaning roller can be compensated for. It is therefore not required to actively take into account such a change due to wear.

The above-described configuration has the advantage that the cleaning roller is fitted in very close vicinity to the rear wall of the housing of the roller cover and therefore also in close vicinity to a dirty liquid receiving device or a suction foot provided behind the roller cover. Provision is therefore specifically not made that the dirt container is provided between the cleaning roller and a dirty liquid receiving device. On the contrary, in the case of the design according to the present disclosure, the dirt container is arranged “in front of” the cleaning roller.

Owing to the fact that the cleaning roller rotates during the operation in such a manner that dirty liquid is conveyed rearwards and therefore towards the suction volume, the problem of dirty liquid building up in front of the roller cover does not occur either.

Furthermore, owing to the fact that only one single cleaning roller is used, it is also avoided that dirty liquid emerges laterally from the roller cover. On the contrary, it is conveyed by the already described selection of the direction of rotation of the cleaning roller in the direction of the rear wall and therefore of a dirty liquid receiving device provided behind the cleaning roller and is thus removed rapidly from the floor surface being cleaned. This dispenses with the necessity of providing squeegees laterally in the roller cover, and therefore the roller cover has a width which is only slightly larger than the width of the region which is actually in engagement with the cleaning roller. Finally, an advantage of the unusual design according to the present disclosure with just one brush roller is that a large roller brush diameter can therefore be used and larger/coarser dirt can be conveyed and the roller can readily enter into unevennesses in the floor. The larger diameter also makes it possible to achieve a greater filling height in the dirt container; that is to say, the dirt container can be loaded to a greater extent than would be the case with small brush rollers. In some examples, the at least one cleaning element comprises a multiplicity of bristles which extend away radially from the roller core, wherein, when the cleaning roller is driven by the drive, the bristles extending through the opening move towards the rear wall. In some examples, the cleaning roller is therefore designed as a brush roller, such a design having proven advantageous and efficient for removing dirt from a conventional floor surface. However, the present disclosure is not restricted to brush rollers, but rather it is also conceivable for the cleaning elements to be designed in some other way, for example as pads or the like.

The dirt strip arrangement can be held movably on the housing wall arrangement in such a manner that the distance of the bottom edge from the longitudinal axis, as seen perpendicularly to the longitudinal axis and perpendicularly to the plane of the opening, can be automatically changed by contact of the dirt strip arrangement, preferably of the bottom edge, with a floor surface to be cleaned. It is therefore preferably provided within the scope of the disclosure that the position of the dirt strip arrangement relative to the housing can be changed by the bottom edge of the dirt strip arrangement or else a guide wheel coming into contact with the floor surface being cleaned and, whenever the housing is lowered towards the floor surface, the dirt strip arrangement does not provide any significant resistance to such a lowering, but rather is displaced in relation to the housing.

Furthermore, it is preferred that the distance of the bottom edge from the longitudinal axis, as seen perpendicularly to the longitudinal axis and perpendicularly to the plane of the opening, can be changed in a region which has an upper and a lower boundary, wherein a pretensioning device is provided which pretensions the dirt strip arrangement into a position in which the distance of the bottom edge from the longitudinal axis, as seen perpendicularly to the longitudinal axis and perpendicularly to the plane of the opening, is at maximum within the region. The pretensioning device is therefore configured in such a manner that it pretensions the dirt strip arrangement away from the cleaning roller and therefore ensures that the bottom edge of the dirt strip arrangement is in contact with the floor surface being cleaned such that it is prevented that dirty liquid is hurled by the rotating cleaning roller “under” the dirt strip arrangement.

In some examples, the dirt strip arrangement has a holder and a flexible sheetlike dirt strip element which has the bottom edge and which is fitted releasably to the holder, and wherein the holder is fastened preferably releasably to a holding element which is held movably on the housing wall arrangement. This two-part design of holder and dirt strip element, on the one hand, and holding element, on the other hand, makes it possible for the element on which the bottom edge is provided and which is exposed to wear to be able to be changed in a simple manner. All that is required here is for the holder to first of all be detached from the holding element, which is held movably on the housing, and then the dirt strip element to be exchanged.

Furthermore, it is preferred that the dirt strip element runs in an upwardly inclined manner from the bottom edge to the housing and away from the cleaning roller. The effect achieved by this is that movement of the cleaning roller causes dirt-laden liquid and coarse dirt to be hurled on a trajectory around the cleaning roller such that they reliably reach the dirt container.

In some examples, the dirt strip arrangement on the holder has at least one rotatable guide wheel, wherein the at least one guide wheel is fitted to the holder in such a manner that, whenever the bottom edge rests on a floor surface to be cleaned, the guide wheel also rests on the floor surface to be cleaned. The effect achieved by the guide wheel is that the dirt strip element does not have to bear the entire load of the dirt strip arrangement, but rather part of said load is absorbed by the guide wheel. As a result, the wear at the dirt strip element is reduced.

Furthermore, it is preferred that the holding element is held on the rear wall so as to be displaceable between a retracted position and an extended position, the distance of the bottom edge from the longitudinal axis, as measured perpendicularly to the longitudinal axis and perpendicularly to the opening, is smaller in the retracted position than in the extended position. In some examples, the height-adjustability of the dirt strip arrangement is realized in a simple manner in that the holding element is fitted displaceably and therefore in a guided manner to the rear wall of the housing. Furthermore, it is preferred that a first and a second lever arm are coupled pivotably to the rear wall, the free ends of which lever arms are coupled to the holding element such that, by pivoting of the lever arms in relation to the housing, the holding element is displaced in a direction perpendicular to the opening. In this way, the guiding of the holding element is realized in a simple manner. It is possible here for the lever arms to be spring-pretensioned in relation to the housing in such a manner that they pretension the holding element towards a floor surface being cleaned. As a result, the holder is pressed with the dirt strip element towards the floor surface being cleaned.

Furthermore, it is preferred that the dirt container can be pushed through an opening in one of the side walls as far as an end position in the housing interior and can be pulled out of the housing interior from the end position, wherein, in the end position, the dirt container extends over the entire length of the cleaning roller. A lateral dirt container which can be pushed in has the advantage that it can easily be removed from the roller cover, even when the latter is fitted to a floor-cleaning machine since the lateral region of the roller cover is easily accessible.

In order to ensure that the roller cover is operated, i.e. the drive for the cleaning roller is switched on, only when the dirt container is also mounted correctly in the roller cover, it is furthermore preferred that an end switch is provided on the housing wall arrangement, said end switch being arranged in such a manner that it is in a first position when the dirt container is in the end position, and is moved out of the first position when the dirt container is not in the end position. Depending on the position of the end switch, a signal can be generated which permits the roller cover to be operated only when the end switch is in the first position.

In some examples, a detection element is provided and arranged in such a manner that it extends into the dirt container, wherein the detection element is displaceable between a first position and a second position, wherein an end of the detection element facing the dirt container is closer to a base of the dirt container in the first position than in a second position, wherein a detection device is provided which is configured to detect whether the detection element is in the first position or in a position remote from the first position, and wherein the detection device is configured to generate a first signal when the detection element is in the first position, and to generate a second signal when the detection element is in a position remote from the first position. With the aid of the detection element, it can be determined how high the level of dirt in the dirt container is. If it is determined with the aid of the detection device that the level in the dirt container has exceeded a maximum height, a second signal can be generated with this example that indicates to the user that the dirt container has to be emptied.

Finally, the present disclosure provides a floor-cleaning machine, with a running gear with wheels such that the running gear is configured to be moved over a floor surface being cleaned, and with a machine housing, wherein a roller cover according to one or more of the previously described examples is held on the machine housing in such a manner that the cleaning roller can engage with the floor surface being cleaned, wherein the housing is held displaceably on the machine housing in such a manner that it can take up different positions along a vertical direction which extends away vertically from the floor surface being cleaned, wherein a position detection device is provided which is configured to detect the position of the housing relative to the machine housing in the vertical direction, and wherein the position detection device is configured to output a predetermined signal if the distance of the housing from the floor surface being cleaned falls below a predetermined value. In this example, it is possible for the degree of wear of the at least one cleaning element on the cleaning roller to be detected by determining the position of the roller cover relative to the machine housing.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

DRAWINGS

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1 shows a side view of the exemplary embodiment of a floor-cleaning machine according to the present disclosure with an exemplary embodiment of a roller cover according to the present disclosure,

FIG. 2 shows a side view of the exemplary embodiment of the roller cover of the floor-cleaning machine from FIG. 1 ,

FIG. 3 shows a sectional view from the side of the exemplary embodiment of the roller cover of the floor-cleaning machine from FIG. 1 ,

FIG. 4 shows a perspective illustration from the rear of the exemplary embodiment of the roller cover of the floor-cleaning machine from FIG. 1 ,

FIG. 5 shows an exploded illustration of the exemplary embodiment of the roller cover of the floor-cleaning machine from FIG. 1 ,

FIG. 6 shows a perspective illustration from in front of the exemplary embodiment of the roller cover of the floor-cleaning machine from FIG. 1 , and

FIGS. 7A-7C show a plurality of lateral sectional views of the exemplary embodiment of the roller cover of the floor-cleaning machine from FIG. 1 .

Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.

DETAILED DESCRIPTION

With reference to FIG. 1 , an exemplary floor-cleaning machine 1 constructed in accordance with the teachings of the present disclosure is illustrated. The floor-cleaning machine 1 has a machine housing 3 in which a dirty liquid container and a cleaning liquid container (neither illustrated) are accommodated. Furthermore, the machine housing 3 is carried by a running gear 5 which has two rear wheels 7, which are driven independently of each other, and a front wheel 9, which is freely pivotable. Owing to the fact that the rear wheels 7 are driveable independently of each other, the floor-cleaning machine 1, which is designed in the present exemplary embodiment as an autonomously driving machine, can be moved over a floor surface 11 being cleaned, with the floor-cleaning machine 1 also being able to be steered.

Furthermore, it can already be seen in FIG. 1 that a roller cover 13 is held on the machine housing 3, wherein the position of the roller cover 13 can be adjusted in a direction perpendicular to the floor surface 11 being cleaned and on which the floor-cleaning machine 1 is arranged. Furthermore, in the rear region of the floor-cleaning machine 1 there is provided a dirty liquid receiving device 15 in the form of a suction foot with which dirty liquid located on the floor surface 11 being cleaned can be picked up and conveyed into the dirty liquid container.

Finally, in the front region of the floor-cleaning machine 1, “side brooms 17” are fitted on both sides of the front wheel 9 and are driven rotationally and sweep the coarse dirt located on the floor surface 11 being cleaned towards the centre of the travel path along which the floor-cleaning machine 1 moves.

As is furthermore revealed in FIGS. 2 to 6 , the roller cover 13 of the exemplary embodiment of a floor-cleaning machine 1 according to the present disclosure has a housing 19 which comprises a housing wall arrangement and at least partially surrounds, and therefore delimits, a housing interior 21, wherein the housing wall arrangement has, inter alia, a rear wall 23 and two side walls 25, 27 which extend away forwards from the rear wall 23 parallel to each other.

As is furthermore revealed in FIGS. 2 and 6 , a mounting opening 29 is provided in the right side wall 25, as seen from the rear wall 23, said mounting opening being able to be closed by a cover 31 and via which the housing interior 21 is accessible from the side. Finally, the housing 19 has an opening 33 in its base, i.e., in the surface which, during the operation of the floor-cleaning machine 1, faces the floor surface 11 being cleaned.

A cleaning roller in the form of a brush roller 35 is accommodated in the housing interior 21, wherein the brush roller 35 has a roller core 37 which extends along a longitudinal axis 39, wherein bristles 41 extending radially outwards are fitted to the roller core 37. The brush roller 35 is arranged here in the housing interior 21 in such a manner that the longitudinal axis 39 runs parallel to the rear wall 23 and the brush roller 35 extends between the side walls 25, 27. Furthermore, the bristles 41 are dimensioned in such a manner that they extend through the opening 33 in the base of the housing 19 outwards to a floor surface 11 being cleaned, as is revealed in particular in FIG. 1 .

A drive 43, which is designed in the exemplary embodiment illustrated here as a motor, is provided on the upper side of the housing 19 of the roller cover 13, wherein the drive 43 is connected via a belt drive, not illustrated in detail, to the brush roller 35 such that the latter, as illustrated by the arrow pointing in the direction of rotation 45 in FIG. 2 , is driven rotationally in such a manner that that part of the bristles 41 which extend through the opening 33 to the floor surface 11 being cleaned moves towards the rear wall 23. The drive 43 is therefore configured in such a manner that that part of the cleaning roller which extends through the opening 33, namely the bristles 41, when the roller 35 is driven by the drive 43, rotates towards the rear wall 23.

Furthermore, it can be gathered from FIGS. 2 to 6 that in the housing interior 21 a dirt container 47 is accommodated displaceably in the transverse direction of the housing 19, i.e., perpendicularly to the side walls 25, 27. The dirt container 47 is arranged on that side of the brush roller 35 which faces away from the rear wall 23 and therefore in the front part of the housing 19. The dirt container 47 extends through the housing interior 21 over the entire length of the brush roller 35 and parallel to the longitudinal axis 39 thereof. In addition, an end switch 49 is fitted to the housing wall arrangement, said end switch being moved by an actuating element 51 on the dirt container 47 from a first position, which the end switch takes up when the actuating element 51 is not in the region of the end switch 49, into a second position when the dirt container 47 has reached the end position in which it is completely pushed into the housing interior 21. It can therefore be detected by the end switch 49 whether the dirt container 47 is in the end position and has therefore been pushed completely into the housing interior 21.

Furthermore, it is revealed in FIG. 3 that a detection element 53 is provided on the machine housing 3, said detection element being held on the machine housing 3 so as to be displaceable substantially in the vertical direction, i.e., during the operation perpendicularly to the floor surface 11 being cleaned, between a first position and a second position. The detection element 53 extends into the dirt container 47 and to the base 55 thereof such that a free end 57 of the detection element 53 that faces the base 55 of the dirt container 47 can take up a different distance from the base 55. If dirt is located in the dirt container, the detection element 53 is moved upwards to the second position in comparison to a first position, in which the free end 57 is at the closest to the base 55. This change in the position of the detection element 53 can be detected by a detection device 59 which is likewise fitted to the machine housing 3. The detection device 59 is configured in such a manner that it generates a first signal when the detection element 53 is in the first position, i.e., is in the vicinity of the base 55 of the dirt container, and a second signal differing from the first signal when the detection element is in a second position remote from the first position. In this way, the detection device 59 can generate a signal which indicates to a user that the dirt container 47 is full and should be emptied.

It can also be seen from FIGS. 2 to 6 that a spray device having two nozzles 61 is provided on the housing 19 and can be used to apply cleaning liquid to the floor surface 11 being cleaned, wherein the nozzles 61 are oriented in such a manner that they apply liquid to the floor surface 11 being cleaned on that side of the housing 19 which is remote from the rear wall 23 and therefore in the region of the front side of the housing 19. The spray device with the nozzles 61 is connected here to the cleaning liquid container in the machine housing 3 via lines.

Finally, FIGS. 2 to 5 and FIGS. 7A-7C show that a holding element 63 is fitted to the rear wall 23 of the housing 19 in such a manner that it is displaceable over a region in a manner yet to be described along the rear wall 23 in a vertical direction, i.e. whenever the roller cover 13 is arranged with a floor-cleaning machine 1 on a floor surface 11 being cleaned, substantially perpendicularly to said floor surface 11. In addition, a holder 65 is provided which can be fastened detachably, but fixedly, to the holding element 63 with the aid of toggle lever arrangements 67, wherein, for this purpose, pins 69 on the holding element 63 engage with keyhole-shaped openings 71 in the holder 65.

A dirt strip element 73 is fastened in turn to the holder 65 with the aid of clamping elements 75, the dirt strip element 73 being sheetlike and flexible and having a bottom edge 77 which extends parallel to the longitudinal axis 39 of the brush roller 35 and is provided to be placed on the floor surface being cleaned when the roller cover is moved together with a floor-cleaning machine 1 over the floor surface 11 being cleaned.

Since the holding element 63 is held displaceably on the housing 19, the dirt strip arrangement comprising the holding element 63, the holder 65 and the dirt strip element 73 can be moved along the rear wall 23 between a retracted position and an extended position in such a manner that the distance of the bottom edge 77 from the longitudinal axis 39, as seen perpendicularly to the longitudinal axis 39 and also perpendicularly to the plane of the opening 33 which is provided in the base of the housing 19, can be changed. The distance of the bottom edge 77 from the longitudinal axis 39 is smaller in the retracted position than in the extended position. The connection between the holding element 63 and the rear wall 23 is configured in such a manner that the resistance which is provided against a movement of the holding element 63 relative to the housing 19 is so small that, whenever the roller cover 13 is placed onto a floor surface being cleaned, the dirt strip arrangement 63, 65, 77 is readily displaced upwards such that the distance between the bottom edge 77 and the longitudinal axis 39 is reduced.

Furthermore, it can be seen in FIGS. 4 and 5 that, in some examples, lever arms 79 are coupled pivotably to the housing 19 and can be pretensioned in the pivoting direction in such a manner that their free ends 81 exert a force downwards anticlockwise, as seen in FIG. 4 , on the holding element 63 to which the free ends 81 are pivotably connected at coupling points 83. The spring-pretensioned lever arms 79 therefore also provide a pretensioning device which pretensions the dirt strip element arrangement 63, 65, 73 into a position in which the distance of the bottom edge 77 from the longitudinal axis 39 is at maximum within the region in which the holding element 63 is displaceable in relation to the rear wall 23. However, it is also conceivable for the spring pretensioning of the lever arms 79 in relation to the housing 19 to be dispensed with.

In addition, it can be seen in FIGS. 1 and 4 that guide wheels 85 are fitted to the holder 65 in such a manner that they likewise rest on a floor surface 11 being cleaned if this is the case for the bottom edge 77 of the dirt strip element 73. The guide wheels 85 therefore support the dirt strip arrangement 63, 65, 73 in relation to the floor surface 11 being cleaned and thereby reduce the wear which occurs when the dirt strip element 73 slides over a floor surface 11 being cleaned. In addition, it is prevented that the dirt strip element can turn over to the rear.

Finally, it can be gathered from FIG. 1 that the floor-cleaning machine 1 has a position detection device 87 with which, in a manner known per se, the position of the roller cover 13 in a direction which runs substantially perpendicularly to a floor surface 11 being cleaned, when the floor-cleaning machine 1 is arranged thereon, relative to the machine housing 3 is detected. This device 87 can be configured in particular such that it outputs a predetermined signal when the distance of the housing 19 of the roller cover 13 from the machine housing 3 exceeds a predetermined value. This is the case when the bristles 41 of the brush roller 35 are worn to too great an extent. In this exemplary embodiment, the floor-cleaning machine 1 is therefore configured in such a manner that, from the vertical position of the roller cover 13 relative to the machine housing 3, it determines the state of the brush roller 35 at least to the extent of whether the brush roller 35 is still usable or is worn too much.

In the operation of the floor-cleaning machine 1, when the latter is moved by means of the running gear 5 over a floor surface 11 being cleaned, the free ends of the bristles 41 of the brush roller 35 of the roller cover 13 are in engagement with the floor surface 11 being cleaned and the brush roller 35 is driven rotationally, the latter rotates in the direction of rotation 45 indicated by the arrow (see FIGS. 2 and 7 ). As a result, dirt located on the floor surface 11 is first of all hurled in the direction of the rear wall 23 and around the brush roller 35 and enters the dirt container 47. This is facilitated by the fact that the dirt strip element 73 is arranged in such a manner that it extends in an upwardly inclined manner from the bottom edge 77 towards the housing 19 and away from the brush roller 35 towards the rear wall 23. The direction of rotation 45 of the brush roller 35 means that the rotation of the brush roller 35 does not provide any resistance to the movement of the floor-cleaning machine 1, said movement taking place in the direction of movement 89 indicated by an arrow in FIG. 2 . In addition, it is avoided by the direction of rotation 45 selected in this way that dirty liquid located on the floor surface 11 being cleaned builds up in front of the roller cover, i.e., on the right side in FIG. 2 . On the contrary, the dirty liquid is conveyed to the rear in the direction of the dirty liquid receiving device 15 (see FIG. 1 ). Finally, the arrangement of the brush roller 35 in the vicinity of the rear wall 23, as seen in the direction of movement 89 of the floor-cleaning machine 1, makes it possible for the brush roller 35 to be able to be arranged in very close vicinity to the dirty liquid receiving device 15.

Finally, the effect achieved by the displaceability of the dirt strip arrangement 63, 65, 73 relative to the housing 19 is that the bottom edge 77 of the dirt strip element 73 of the dirt strip arrangement 63, 65, 73 rests on a floor surface 11 being cleaned irrespective of the degree of wear of the bristles 41 of the brush roller 35. This is illustrated in particular in FIGS. 7A-7C.

It can be seen there in part a) that the dirt strip arrangement 63, 65, 73 is displaced relative to the housing 19 in the vertical direction with respect to the floor surface 11 being cleaned such that the bottom edge 77 of the dirt strip element 73 is at a comparatively large distance 91 from the longitudinal axis 39 of the brush roller 35, said distance 91 being measured perpendicularly to the longitudinal axis 39 and also perpendicularly to the plane of the opening 33. If the bristles 41 become further worn, as is shown in FIGS. 7B and 7C, the roller cover 13 is lowered further towards the floor surface 11 being cleaned, with the dirt strip arrangement 63, 65, 73 being displaced along the rear wall 23 of the housing 19 in such a manner that the distance of the bottom edge 77 from the longitudinal axis 39 decreases. If this distance 91 falls below a predetermined value, the distance of the housing 19 from the machine housing 3 also exceeds a predetermined value, which can be detected by the position detection device 87. This triggers a wear signal for a user who can then exchange the brush roller 35 through the opening 33 in the housing 19.

The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

List of Reference Signs 1 Floor-cleaning machine 3 Machine housing 5 Running gear 7 Rear wheel 9 Front wheel 11 Floor surface being cleaned 13 Roller cover 15 Dirty liquid receiving device 17 Side broom 19 Housing 21 Housing interior 23 Rear wall 25 Side wall 27 Side wall 29 Mounting opening 31 Cover 33 Opening 35 Brush roller 37 Roller core 39 Longitudinal axis 41 Bristles 43 Drive 45 Direction of rotation 47 Dirt container 49 End switch 51 Actuating element 53 Detection element 55 Base 57 Free end - detection element 59 Detection device 61 Nozzle 63 Holding element 65 Holder 67 Toggle lever arrangement 69 Pin 71 Keyhole-shaped opening 73 Dirt strip element 75 Clamping element 77 Bottom edge 79 Lever arm 81 Free end - lever arm 83 Coupling point 85 Guide wheel 87 Position detection device 89 Direction of movement 

What is claimed is:
 1. A roller cover for a floor-cleaning machine (1), with a housing (19), wherein the housing (19) has a housing wall arrangement which delimits a housing interior (21) and which comprises a rear wall (23) and two opposite side walls (25, 27) and which has an opening (33) which is arranged so as, during the operation of the roller cover (13), to face a floor surface (11) to be cleaned, with a cleaning roller (35) (39), which extends along a longitudinal axis and has at least one cleaning element (41) radially on the outside, wherein the cleaning roller (35) extends along its longitudinal axis (39) through the housing interior (21) from the first side wall (25) to the second side wall (27), wherein the at least one cleaning element (41) of the cleaning roller (35) extends through the opening (33), with a drive (43) which is coupled to the cleaning roller (35) in order to drive the latter rotationally, wherein the drive (43) is configured in such a manner that, whenever the cleaning roller (35) is driven, that part of the cleaning roller (35) which is provided to engage with a floor surface (11) to be cleaned rotates towards the rear wall (23), wherein a dirt container (47) is arranged in the housing interior (21) on that side of the cleaning roller (35) which faces away from the rear wall (23), wherein fitted to the housing wall arrangement is a dirt strip arrangement (63, 65, 73) which has a bottom edge (77) which runs parallel to the longitudinal axis (39) and is configured to rest on a floor surface (11) to be cleaned, wherein the dirt strip arrangement (63, 65, 73) is held on the housing wall arrangement in such a manner that the bottom edge (77) is arranged on that side of the longitudinal axis (39) of the cleaning roller (35) which faces the rear wall (23), and wherein the dirt strip arrangement (63, 65, 73) is held movably on the housing wall arrangement such that the distance (91) of the bottom edge (77) from the longitudinal axis (39), as seen perpendicularly to the longitudinal axis (39) and perpendicularly to the plane of the opening (33), can be changed.
 2. A roller cover according to claim 1, wherein the at least one cleaning element comprises a multiplicity of bristles (41) which extend away radially from a roller core (37) extending along the longitudinal axis (39), and wherein, when the cleaning roller (35) is driven by the drive, the bristles (41) extending through the opening move towards the rear wall (23).
 3. A roller cover according to claim 1, wherein the dirt strip arrangement (63, 65, 73) is held movably on the housing wall arrangement in such a manner that the distance (91) of the bottom edge (77) from the longitudinal axis (39), as seen perpendicularly to the longitudinal axis (39) and perpendicularly to the plane of the opening (33), can be automatically changed by contact of the dirt strip arrangement (63, 65, 73), preferably of the bottom edge (77), with a floor surface (11) to be cleaned.
 4. A roller cover according to claim 1, wherein the distance of the bottom edge (77) from the longitudinal axis (39), as seen perpendicularly to the longitudinal axis and perpendicularly to the plane of the opening (33), can be changed in a region, and wherein a pretensioning device (79) is provided which pretensions the dirt strip arrangement (63, 65, 73) into a position in which the distance (91) of the bottom edge (77) from the longitudinal axis (39), as seen perpendicularly to the longitudinal axis (39) and perpendicularly to the plane of the opening (33), is at maximum within the region.
 5. A roller cover according to claim 1, wherein the dirt strip arrangement has a holder (65) and a flexible sheetlike dirt strip element (73) which has the bottom edge (77) and which is fitted releasably to the holder (65), and wherein the holder (65) is fastened preferably releasably to a holding element (63) which is held movably on the housing wall arrangement.
 6. A roller cover according to claim 1, wherein the dirt strip element (73) runs in an upwardly inclined manner from the bottom edge (77) to the housing (19) and away from the cleaning roller (35).
 7. A roller cover according to claim 5, wherein the dirt strip arrangement (63, 65, 73) on the holder (65) has at least one rotatable guide wheel (85), wherein the at least one guide wheel (85) is fitted to the holder (65) in such a manner that, whenever the bottom edge (77) rests on a floor surface (11) to be cleaned, the guide wheel (85) also rests on the floor surface (11) to be cleaned.
 8. A roller cover according to claim 5, wherein the holding element (63) is held on the rear wall (23) so as to be displaceable between a retracted position and an extended position, wherein the distance (91) of the bottom edge (77) from the longitudinal axis (39), as measured perpendicularly to the longitudinal axis (39) and perpendicularly to the opening (33), is smaller in the retracted position than in the extended position.
 9. A roller cover according to claim 8, wherein a first and a second lever arm (79) are coupled pivotably to the rear wall (23), the free ends (81) of which lever arms are coupled to the holding element (63) such that, by pivoting of the lever arms (79) in relation to the housing (19), the holding element (63) is displaced in a direction perpendicular to the opening (33).
 10. A roller cover according to claim 1, wherein the dirt container (47) can be pushed through an opening in one of the side walls (25, 27) as far as an end position in the housing interior (21) and can be pulled out of the housing interior (21) from the end position, and wherein, in the end position, the dirt container (47) extends over the entire length of the cleaning roller (35).
 11. A roller cover according to claim 10, wherein an end switch (49) is provided on the housing wall arrangement, said end switch being arranged in such a manner that it is in a first position when the dirt container (47) is in the end position, and is moved out of the first position when the dirt container (47) is not in the end position.
 12. A roller cover according to claim 1, wherein a detection element (53) is provided and arranged in such a manner that it extends into the dirt container (47), wherein the detection element (53) is displaceable between a first position and a second position, wherein an end of the detection element (53) facing the dirt container (47) is closer to a base (55) of the dirt container (47) in the first position than in a second position, wherein a detection device (59) is provided which is configured to detect whether the detection element (53) is in the first position or in a position remote from the first position, and wherein the detection device (53) is configured to generate a first signal when the detection element (53) is in the first position, and to generate a second signal when the detection element (53) is in a position remote from the first position.
 13. A floor-cleaning machine with a running gear with wheels such that the running gear (5) is configured to be moved over a floor surface (11) to be cleaned, and with a machine housing (3), wherein a roller cover (13) according to claim 1 is held on the machine housing (3) in such a manner that the cleaning roller (35) can engage with the floor surface (11) to be cleaned, wherein the housing (19) is held displaceably on the machine housing (3) in such a manner that it can take up different positions along a vertical direction which extends vertically away from the floor surface (11) to be cleaned, wherein a position detection device (87) is provided which is configured to detect the position of the housing (19) relative to the machine housing (3) in the vertical direction, and wherein the position detection device (87) is configured to output a predetermined signal if the distance of the housing (19) from the machine housing (3) exceeds a predetermined value. 